To address the issues of reservoir pore-throat blockage and permeability decline caused by asphaltene deposition during CO₂ flooding in low-permeability reservoirs，this study proposes a novel technical approach utilizing nanomaterials to inhibit asphaltene deposition. Using graphene oxide （GO），aniline，and decylamine as raw materials，modified nano-graphene oxide （GO-BD） was prepared via covalent grafting. Systematic asphaltene dispersion experiments and online CO₂ flooding experiments based on low-field nuclear magnetic resonance （NMR） were conducted to evaluate its effectiveness in inhibiting asphaltene deposition. The research results showed that the GO-BD obtained via GO modification exhibited good hydrophobicity. GO-BD had excellent performance in inhibiting asphaltene deposition，which could significantly delay the onset of asphaltene precipitation and reduce the size of asphaltene aggregates. At a GO-BD mass concentration of 25 mg/L，the asphaltene precipitation point of the oil sample increased from 42 . 03 % to 58 . 27 %，and the particle size of asphaltene aggregates decreased from 1297 nm to 537 nm. During CO₂ flooding，compared with pure CO₂ injection，the addition of 0 . 8 % mass fraction of GO-BD inhibitor to crude oil reduced core permeability damage rate by 20 . 8 %，decreased pore blockage rate by 7 % — 10 %，and enhanced oil recovery by more than 10 percentage points. This research provides reference and guidance for the application of nanofluid materials to inhibit asphaltene deposition during CO₂ flooding.